A whole house water softener removes minerals from all the water in a house.
Water softening systems use a process called ion exchange to remove calcium and magnesium, which are characteristic of hard water. Excessively hard water can make household cleaning difficult, often leaving dirty kitchen and bathroom utensils, dull clothes and stains on dishes. Water softener should be used with care, as it exchanges sodium for minerals that give water hardness characteristics and can be harmful to people on low-sodium diets. Sodium produced by softening water can also be harmful to plants. All of the different types of water softener systems use ion exchange, but they vary in the amount of input they require from the operator.
Water softener should be used carefully as it exchanges sodium for minerals that give water its hardness.
Hard water originates from underground sources like aquifers because calcium, magnesium, and other minerals dissolve into the water from surrounding rocks. Calcium and magnesium cause so-called hard characteristics. Hardness is measured in grains per gallon (GPG), with a grain of hardness equal in weight to a grain of wheat. Any water with more than 1 GPG of calcium and magnesium is considered hard, and more than 10.5 GPG is classified as very hard.
Chemicals can be added to laundry detergent to help soften the water used to wash clothes.
Chemicals are sometimes added to laundry detergent to soften the water used for washing clothes, but all water softener systems that treat the water used throughout a home use ion exchange. An ion is an electrically charged molecule and different ions can have different intensities of charge. Water softeners contain an exchange medium, which starts out coated with positively charged sodium ions. The calcium and magnesium ions in hard water also have a positive charge, but they have a stronger charge than the sodium ions. This means that when water passes through the exchange medium, calcium and magnesium ions are captured by the medium, while sodium ions are released, since calcium and magnesium ions have a stronger attraction.
Eventually, the exchange medium in a water softening system becomes completely covered with calcium and magnesium ions. When this happens, the fabric softener is washed out with a sodium chloride solution, a process known as recharging. Calcium and magnesium ions form compounds with chlorine and are washed away, while sodium ions re-bind to the exchange medium.
The different types of water softener systems vary depending on the amount of work the user needs to do to refill them. The most popular type of home water softeners are automatic softeners, also called fully automatic softeners, which use a timer set by the owner to automatically recharge the system. Another type of water softener that works automatically is demand-initiated regeneration (DIR), which determines when to recharge the system based on how much water has been used.
Manual and semi-automatic systems require more input from the user. A semi-automatic water softener requires the owner to manually tell the softener when to refill. Manual water softeners require the user to set all parameters to recharge the softener, including when the system recharges and for how long.